Exercise may improve the effectiveness of an anti-cancer drug

Periods of moderate to vigorous exercise may improve the effectiveness of antibody therapy used to treat chronic lymphocytic leukemia (CLL), a new study finds.

Researchers from the Universities of Birmingham and Bath found that exercise increases the number of anti-cancer immune cells called natural killer cells, and that these cells were almost twice as effective at killing cancer cells in "ex vivo" tests carried out on patients' blood samples..

In addition, the researchers found that the number of cancer cells in blood samples temporarily increased immediately after exercise, making them more vulnerable to attack by natural killer cells and antibody therapy.

This study may open up new possibilities for antibody treatments for some forms of cancer, although more research is needed to determine the effects in vivo in patients undergoing treatment.

Dr James Turner, co-author of the study from the University of Birmingham, said: “These results show potential benefits for patients undergoing certain types of treatment and could open new lines of research to explore whether exercise can improve the effectiveness of other cancer treatments. "

In a study published in the journal Brain, Behavior, and Immunity, researchers wanted to test the effects of exercise on an antibody therapy called Rituximab. It is a common treatment for chronic lymphocytic leukemia, which is a cancer of white blood cells and the second most common adult form of blood cancer in the UK. The therapy works by attaching to a specific protein on the surface of cancer cells, which natural killer cells can recognize and attack.

The researchers worked with 20 people aged 45 to 82 who had been diagnosed with chronic lymphocytic leukemia but had not yet started treatment. Participants were asked to engage in 30 minutes of moderate-intensity cycling. Blood samples were taken before and immediately after exercise, and then another sample was taken an hour later.

In ex vivo blood samples, the researchers measured the number of natural killer cells in each sample and tested their ability to kill cancer cells with and without Rituximab.

They found that the number of natural killer cells increased by 254% after exercise, and that blood samples taken after exercise had 67% more cancer cells compared to samples before exercise.

The team then isolated natural killer cells and placed them in direct contact with cancer cells for 2 hours "ex vivo" with and without the presence of the antibody therapy Rituximab. When Rituximab was also present in the blood sample, natural killer cells were more than twice as effective at killing cancer cells in samples collected immediately after exercise compared with samples collected before exercise.

Dr John Campbell, senior author of the study from the University of Bath, said: "Cancer cells often try to 'hide' in the body, but exercise appears to help move them into the bloodstream, where they become vulnerable to antibody therapy and killer cells."

The study results may also be useful for patients who have completed treatment for leukemia and are being monitored for recurrence of cancer cells.

Dr Harrison Collier-Bain, first author of the study from the University of Bath, said: "Monitoring patients after treatment is difficult because if cancer cells remain or reappear, they are sometimes too small to be detected, but a period of exercise beyond which should take a blood sample immediately afterwards can help 'find' them if they are 'hiding' in the body."

Although these results are promising, larger trials in a cohort of patients treated with Rituximab will be required to inform treatment recommendations.

Caroline Geraghty, senior information officer at Cancer Research UK, said: “This study adds to the growing body of evidence showing that exercise can be beneficial before, during and after cancer treatment.

"We know that being physically active before and after treatment can help patients cope better with treatment, promote recovery and improve mental well-being. It's interesting to see that exercise can also improve the effectiveness of treatment for some types of blood cancer, although more research is needed in a larger group of patients.

"Everyone has different needs and abilities, so it is important to discuss with your doctor what forms of exercise are best for you. We encourage all cancer patients to ask their doctor for advice before starting an exercise program before or after treatment. To ensure that the proposed activities are suitable for them."